Process of making photographic films



E. M. FLAHERTY.

PROCESS OF MAKING PHOTOGRAPHIC FILMS.

APPLICATION FILED DEC-5,1918.

1,350,274, Patented Aug. 17,1920.

A UNITED STATES PATENT OFFICE.

EDMUND M. FLAHERTY, OF PARLIN, NEW JERSEY, ASSIGNOR TO E. I. DU POINT Dz N'EMOURS & COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

PROCESS OF MAKING PHOTOGRAPHIC FILMS.

Specification of Letters Patent.

, Patented Aug. 17, 1920.

Application filed December 5, 1918. Serial No. 265,324.

To all whom it may concern Be it known that I, EDMUND M. FLAHERTY of Parlin, in the county of Middlesex, and in the State of New Jersey, have inventeda certain new and useful Improvement in Processes of Making Photographic Films,

' and do hereby declare that the following is a full, clear, and exact description thereof.

My invention relates particularly to a process for the production of nitrocellulose bodies such as photographic films and especially films'which may be used in making moving pictures.

The object of my invention is to provide a process by means of which films or the like and especially photographic films of all kinds and including moving picture films may be manufactured continuously, and so as to produce a product of very high quality. The object of my invention is, furthermore, to provide a nitrocellulose solution from which such films may be readily made, and which may be readily stripped from the fiat or cylindrical revolving surface upon which the film is formed by the evaporation of the solvents contained therein. A further object is to provide a solvent mixture for the nitrocellulose which will deposit a strong film. Another object is to provide solvents which do not evaporate so fast as to form bubbles or wrinkles, but which are sulficiently oily to allow the film to be readily stripped from the. support upon which it is formed. Another object is to use solvents which are comparatively inexpensive, so as to avoid the expense due to the unavoidable losses of solvents in forming films. The object of my invention is, furthermore, to ful-' fill these requirements by the use of a solvent mixture containing normal butyl acetate, and which may contain also normal butyl alcohol.

While -my invention is capable of being carried out in many different ways, for the purpose'of illustration I shall describe only one way of carrying out the same hereinafter.

For example, a moving picture film may be made from a solution of nitrocellulose having the following composition:

Methyl alcohol 50. 6 parts by weight Normal butyl acetate 10 Normal butyl alcohoL- 20. 8 Camphor 2 Nitrocellulose 16. 6

This solution may be deposited upon a continuously revolving drum, and the film produced therefrom may be continuously stripped from the drum, then dried and wound into rolls continuously. The drying may be carried out in any usual manner as by drying in a closed space having an even purpose of illustration I have shown only one form of apparatus for usein connection therewith in the accompanying drawings, in which;

Figure 1, is a diagrammatic plan view (with details of hopper and blade omitted for the sake of clearness) of an apparatus which may 'be used in accordance with my invention, and

Fig. 2, is a diagrammatic elevation with parts omitted and parts in section. In the drawings, there is a hopper 1 designed to feed from the lower end thereof a thin layer of the nitrocellulose solution as above described, upon a continuously revolving drum 2, from which a film 3 may be stripped by a doctor blade 4, and thence preferably conducted over a plurality of rolls 5 to a small drum 6 upon which the film may be wound into a roll. The lower part of the drum may be inclosed in a chamber 7 connected by a pipe 7 to a cooling chamber 8 leading to a condenser 9, and thence to a heating chamber 10. From the condenser 9 the condensate may be carried off by a pipe 11, and the uncondensed gases returned by a pipe 12 to said chamber 7.

lVhile I have described my invention above in detail, I wish it to be understood that many changes may be made therein without departing from the spirit thereof.

Claims:

1. The process which comprises depositing anitrocellulose film from a solution containing nitrocellulose, normal butyl acetate and a diluent.

2. The process which comprises depositing a nitrocellulose film from a solution containing nitrocellulose, normal butyl acetate and normal butyl alcohol.

3. The process which comprises depositing a nitrocellulose film from a solution containing nitrocellulose, normal butyl acetate, a diluent and camphor.

4. The process which comprises depositing a nitrocellulose film from a solution containing nitrocellulose, normal butyl acetate, normal butyl alcohol and camphor.

5. The process which comprises depositing a nitrocellulose film from a solution containing nitrocellulose, normal butyl acetate and a diluent upon a revolving drum.

6. The process which comprises depositing a nitrocellulose film from a solution containing nitrocellulose, normal butyl acetate and normal butyl alcohol upon a revolving drum.

7. The process which comprises depositing a nitrocellulose film from a solution containing nitrocellulose, normal butyl acetate, a diluent and camphor upon a revolving drum.

8. The process which comprises depositing a nitrocellulose film from a solution containing nitrocellulose, normal butyl acetate, normal butyl alcohol and camphor upon a revolving drum.

9. The process which comprises depositing a nitrocellulose film from a solution containing nitrocellulose, normal butyl acetate and a diluent upon a revolving drum, and continuously stripping the film from the drum.

10. The process which comprises depositing a nitrocellulose film from a solution containing nitrocellulose, normal butyl acetate and normal butyl alcohol upon a revolving drum, and continuously stripping the film from the drum.

11. The process which comprises depositing a nitrocellulose film from a solution containing nitrocellulose, normal butyl acetate, a diluent and camphor upon a revolving drum, and continuously stripping the film from the drum.

12. The process which comprises depositing a nitrocellulose film from a solution containing nitrocellulose, normal butyl acetate, normal butyl alcohol and camphor upon a revolving drum, and continuously stripping the film from the drum.

13. The process which comprises deposit- I ing a nitrocellulose film from a solution containing nitrocellulose, normal butyl acetate-and a diluent upon a revolving drum, continuously stripping the film from the drum, and then drying and winding the film into rolls.

l4.- The process which comprises depositing a nitrocellulose film from a solution containing nitrocellulose, normal butyl acetate and normal butyl alcohol upon a revolving drum, continuously stripping the film from the drum, and then drying and winding the film into rolls.

15. The process which comprises depositing a nitrocellulose film from a solution containing nitrocellulose, normal butyl acetate, a diluent and camphor upon a revolving drum, continuously stripping the film from the drum, and then drying and winding the film into rolls.

16. The process which comprises depositing a nitrocellulose film from a solution containing nitrocellulose, normal butyl acetate, normal butyl alcohol and, camphor upon a revolving drum, continuously stripping the film from'the drum, and then dryin and'winding the film into rolls.

In testimony that I claim the foregoing I have hereunto set my hand.

EDLIU ND M. FLAHERTY.

'itnesses W. B. RATLEDGE, CHAS. IV. CHAPPEL. 

